1. Field of the Invention
The present invention relates to a digital living network alliance (DLNA) network and, in particular, to a system and method for transmitting high quality contents broadcasted on a plurality of channels to Internet Protocol (IP) communication-supported devices such as a digital media player (DMP), a mobile phone, personal computer (PC), and etc. which are connected through the DLNA network.
2. Background of the Related Art
Home networking technologies are rapidly developed such that consumer electronics and mobile and PC devices are interoperating in a home to enhance and enrich a user experiences with various services. In order to allow for the interoperability of the household appliances, various middleware, such as Universal Plug and Play (UPnP), Home Audio/Video Interoperability (HAVI), Java Intelligent Network Infrastructure (JINI), Video Electronics Standard Association (VESA), Digital Living Network Alliance, etc., protocols have been developed and are in the process of being adopted.
Among the middlewares, the DLNA formerly called the Digital Home Working Group (DHWG), is an alliance of leading corporate members including, Microsoft (MS), IBM, HP, Intel, Sony, Matsushita, Samsung, etc., established in June 2003. The aim of the DLNA is to align the companies and have industry standards that will allow products from all companies to be compatible and to enable a network of electronic devices such as TV, VCR, digital camera, and audio components in the home. Also, the DLNA has focused on the interoperability between networked entertainment and media devices for personal media uses involving imaging, audio and video.
The DLNA further defines a PC Internet Network where PC and PC peripherals such as a printer may communicate; a Mobile Network of multimedia mobile phones, personal digital assistants (PDAs), MP3 players, laptop computers, and other similar devices provides unparalleled connectivity and freedom of movement into and out of the home environment; a consumer electronic (CE) network of set-top boxes and traditional consumer electronics. Also, to deliver interoperability in the digital home, DLNA has focused on the industry collaboration, standards-based interoperability, and compelling products.
One of the key issues of the DLNA is media management and control that enable devices and applications to identify, manage, and distribute media contents across the stationary home network, or to transmit the identification, management and distribution to mobile device. UPnP Audio/Video (AV) technology addresses all of these needs for the home network and is the media management and control solution for devices developed according to the DLNA interoperability guidelines. Accordingly, DLNA has developed the physical media, network transports, media formats, streaming protocols and digital rights management mechanisms on the basis of UPnP.
The Internetworking for home network according to DLNA is based on Internet Protocol (IP), which provides underlying network communication for devices on the Internet and allows applications running over different media to communicate transparently.
For example, a PC or an advanced set top box (STB) may stream media contents to a TV in a master bedroom through an Ethernet cable to a 802.11 Access Point and then wirelessly to the TV. With IP, all the DLNA devices can communicate with other devices located anywhere around the world through the Internet.
DLNA is likely to be implemented with a wired fast Ethernet (802.11u) and wireless Ethernet (802.11a/b/g) as the physical layer. The wired Ethernet has a proven stability already and the use of wireless Ethernet, i.e., Wi-Fi for wireless home networking is already widely spread.
DLNA is implemented on the basis of UPnP AV architecture and UPnP Device architecture which is used for locating and controlling devices across the DLNA network, i.e., automatically configuring the IP address and recognizing other devices on the network with reference to the IP address, as well as checking and managing services to be provided.
In the meantime, the home network device category is made up of five Device Classes that share system usages in the home network with the same media format and network connectivity requirements. Among them, Digital Media Server (DMS) devices make roles, like the Media Server Device in the UPnP AV specification, for providing media acquisition, recording, storage, and sourcing capabilities, as well as content protection enforcement as required, and Digital Media Player (DMP) devices make roles, like the Media Render Device (MRD) and the Media Renderer Control Point (MRCP), for finding, selecting, and controlling to playback contents exposed by a DMS.
FIG. 1 is a block diagram illustrating a conventional DLNA system to which the present invention is adopted. As shown in FIG. 1, the DLNA system includes a digital media server (DMS) 13 for providing multimedia contents and Digital Media Players (DMPs) 15 and 17 which playback the multimedia contents provided by the DMS 13. The DMS 13 and the DMPs 15 and 16 communicate through Ethernet or IEEE 1394 as wired connections or Bluetooth (BT), IEEE 803.11, or Ultra Wide Band (UWB) as wireless connections. The DMS 13 uses IPv4 or IPv6 for providing contents to the DMP such as mobile phone or personal media player (PMP) 12 and PC or laptop computer 16 through Internet 10 using wired and/or wireless connections. Typically, DMP is a device having both the wired and wireless communication modules. Also, the DMP can have a home gateway function and a control point (CP) function in the home network.
The DMP can be a PC or a mobile phone or the DMS can be a set top box or a network PC such that the DMS 13 retransmits the general broadcast contents to the DMP 15 and 17 through wired or wireless links inside the home or outside wherever IP communication is possible.
In case of retransmitting the TV broadcasting signal to the DMP 15 and 17, the analog TV signal can be retransmitted to the PC using a Sling box method or after converting the signal in a legacy AV device. In this case, the TV or set top box is controlled by the Infra Red (IR) signal.
However, the conventional contents retransmitting method has drawbacks in that it cannot support the high definition (HD) contents or degrades the quality even if it may support HD transmit. In addition, additional configuration for retransmitting the contents in IP environment is needed.
Also, the conventional method is inconvenient in that the DLNA compliant devices are continuously updated since all the AV devices are not compliant to the DLNA, and the devices can be manipulated in a range of IR control around the TV or set top box. Furthermore, in order to playback the retransmitted contents in the PC, a PC program dedicated to such contents should be installed previously.